Improvement in keys for locks



C. H. STEWART.

KEYS FOR LOCKS.

No. 188,827. Patented March 27,1877.

Everzfar; Witnesses. M 9%JM .PETERS, PHDTD-UTHOGRAPHER, WASHINGTON, D.C-

UNITE STATES PATENT OFFICE.

, CHARLES H. STEWART, OF JOHNSTOWN, NEW YORK, ASSIGNOR TO DAVID HAYS,OF- SAME PLACE.

IMPRQVEM ENTJN KEYS FOR LOCKS.

Specification forming part of Letters Patent No. 188,827, dated March27, 1877; application filed I 1 April .7, 1876.

the lock; and it consists in providing'the bit' with a lateralprojection, which engages with thelock-case as the key enters the lock,which gives the bit a quarterturu on its pivot, and;

at the same time a plunger, operated by a spring, holds the bitperpendicular to the axis of the key, the key-bit having two of itsedges at right angles to each other, each of which alternately abutsagainst the forward end of the spring-plunger in the two positions itoccupies-viz., open or closed. When the key is Withdrawn from the lock,the bit comes in contact with the inner side of the lock-case, and isclosed into the key-shaft.

Figure 1 exhibits a longitudinal side elevation, showing the bit open.Fig. 2 is a longitudinal central sectional view of my invention. Fig. 3is a front-end view of the open bit and a slight portion of the bow, andFig. 4 is a plan View of the bit.

Similar letters of reference indicate corresponding parts in the variousfigures.

To enable others skilled in the art to fully understand and construct myinvention, I will give the following description A represents the shaftor barrel to which my invention is applied. Said barrel is also formeddifl'erently from others in general use.

The bow A. has an opening, I), on one side,

while on the opposite side is left a blank space of solid metal, asshown in the drawing, Fig. 1. This I do in order to determine the trueposition of the bit 0, so that the key may be entered into the lock inthe proper way, as will be readily inferred.

The cylindrical portion of the key may be cast solid and then bored out,as will be seen by reference to Fig. 2. Slots or openings should be madethrough the shell thus formed, for the free movement of the pivoted bit0, and lateral or guide projections d d on the plunger E.

The bit 0 is pivoted at the point f, and opens in the direction of thearrow through the bit coming in contact with the lock-case.

- (Represented by dotted lines, Fig. 2.)

The plunger E is forced against the bit 0 by the spiral spring g, asshown in Fig. 2. The projections d d on the plunger E slide in slots inthe barrel A, as before described, in order that the forward end of theplunger may have a broad bearing-surface for the rectangular sides ofthe bit 0, so as to hold the same open or closed, as shown in Figs. 1and 2.

It will be fully understood by Fig. 1 that, on the withdrawal of the keyfrom the lock, the bit 0 will be closed by the same coming in contactwith the inner face of the lock-case, which is shown by dotted lines.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

The combination, in a key provided with a pivoted'bit, of the plunger E.spring 9, and stem A, operating substantially in the manner and for thepurpose set forth.

0. H. STEWART.

Witnesses:

J. W. LATOHER, D. MOMARTIN.

